Method of forming plugs



Dec. 7,' E943. F. c. A. oTT 2,335,879

METHOD oF FORMING PLUGS Filed July 12, 3,940 2 sheets-sheet 1 E A -;51 Ik) .l T- @WE- I In M lNvEN-roR fda/@H4417 TTORNEYS 4 Dec. 7, 1943. F. c. A. o'rT 2,335,879-- METHOD 0F FORMING PLUGS Filed July 12, 1940 v vzsneets-shee'f, 2

ATTORNEYS Patented Dec. 7, 1943 assiale, Mannoia or FoRMiNerLUGs sueca-ick charles August ou, Glendale, N. Y.,

assigner tc Mundet Cork Corporation, Brooklyn, N.,Y.,.a corporation of NewYork Application July 12,1940, serialfNo. 345,088

`:a claims. (c1. isi-59') This invention relates to a method of producing a plug. Moreover, the present invention lcontemplates the design of a machine, by means 'of vwhich-'such method vmay be practiced.

1- It is a primary object of the invention to fur- -nish a plug capable of use in numerous different associations, but of especial utility when employed in connection with ordnancework. Where so employed, the plug will be projected from the 'muzzle of the gun and will, thereafter, substantially immediately disintegrate. Such disintegration will occur to a degree that no fear need befelt of large or-dangerous fragments of the plug constituting amenace to troops over whom the-projectile is being fired.

A further object of the invention iskthat -of `teaching a simple and efflcient method, capable of-being practiced by relatively unskilled labor, Aand as a consequence of which a strong plug may vbeeconomically produced in large quantities.

With these and other objects in mind, reference ishad to the attached sheets of drawings, illustrating one practical embodiment of theinvention, and in which: Y

Fig. 1 is a partly sectional front view ofthe machine for producing plugs;

Fig. 2 is apartly sectional side view thereof;

Fig. 3 is a sectional plan view taken along the lines 3,-3 and in thedirection of thearrows, as indicated in Fig.- 1;

Fig. 4 shows the machine parts in kvinitial or Separated positions; f

Fig. 5 illustrates such parts` at the completion of their working stroke or cycle;

Fig. `r6 is a perspective View of the bed orv support of the machine; y

" Fig. 7 is a sectional side View ofthe plug", to-

gether with the parts which form the same; and Fig. 8 is a bottom plan View of the unit, as

shownin Fig. 7.

Referring primarily to'Fig. 7--the numeral I0 `indicates a core formed, for example, of corkboard, and'which core is preferably tapered, as shown. Surrounding the core is a sleeve II presenting a tapered surface I2 and a surface I3, which latter preferably extends perpendicular to the base of theY ensemble. The sleeve I I is prefer- `-ably formed lof composition cork.

it is well known that by corkboard, it is meanta body formed of a mass-of cork granules secured together Vunder pressurevandheat, andso that the vresins present in such granules act as a binder to cause maintenance of the configuration which is imparted to such body or mass. On the other hand, by a composition cork, there is understood-a mass of cork granules coated with one of any number of dierent adhesives.

While, as afore brought out, a plug of this type may be employed in various different associations, it is of primary utility when utilized in connection With ordnance. More especially in such-use, it is quite customary to employ a case filled with explosive. This explosive is maintained against displacement usually by a partition member of any desired construction. The projectile is disposed beyond the case, andthe present plug is interposed between the projectile andthe partition member. Ordinarily, the plug may extend into the case. In any event, .with the firing of the charge, the thrust is transmitted through the plug to the projectile and both are discharged from the muzzle of the rifle. By having the unit formed preferably of corkboard and composition cork, it is found that while the plug is, in every respect, sufciently strong to fulfill all purposes for which'it is intended, it will embody the characteristic that, immediately after 'its discharge from the muzzle, it will disintegrate.

In order to facilitate the handling of the plug, and allow for its association with the case, the inclined surface I2 of such plug may be graphited.

4The surface I3 may be coated with lacquer or Ashellac in order to seal such surface. The disvbody of the co-re IG, to prevent displacement of the latter. Encircling the sleeve Il of cork comadjacent surface of the core lll. The lower edge -of this shell is preferably extended outwardly, `as indicated aty I3. Realizing that sleeve I I would lbe under compression, and with 'a view to retaingin'gv the cap I4 and'shell against displacement Ait may slip over the tube or bed.

with respect to each other, rods I 9 may be passed through openings in the latter and engage the base ofthe former.

With a View to bringing the cap and shell to the condition shown in Fig. 7, and to correspondingly compress and assemble the materials disposed Within these parts, a mechanism, such as is primarily shown in Figs. 4, and 6, is employed. Inthese views, the numeral indicates a bed, or support, preferably in the nature of a tube and which, adjacent its upper end, is conveniently formed to provide an inner and outwardly extending ange portion 2I of aheight corresponding substantially to the distance be-V tween the ange I3 of the shell andthe base of the cap I4. This flange, and: also the body of the tube 20 adjacent the same, may be formed with slots 22 of a depth such that the rods or pins I9 may conveniently be passed through the shell. thevdiameter of the tube or bed 20 is preferably substantially equal to `that of the cap I 4, while the internal diameter of the shell is such that A filling tube 23-is slidably mounted and capable of being telescoped over the tube 24J. The length of tube 23 is less than that of the tube 20 and a stop member 2d may be provided and which will maintain tube 23 in elevated position.

A core pipe 25 may be supported upon the core I0, and a pressure cylinder 26 may be disposed .above this pipe 25. The lower inner surface of the cylinder 2S may conform generally to the upper surface of the mold shell and have a diam- .eter` less than that of the body portion I Sthlereof.

lthe space intervening the core and core pipe and `the filling tube has received a charge of composition cork. This charge may, in aggregata, be anywhere up -to Vthree times the heightY which .the finished plug is to have.

Thereafter, and with the shell positioned upon the lling tube, the pressure cylinder 26 is shiftedto a point at which it engages the shell, as shown in Fig. e. If now, the catch or latch24 is released, and the cylinder is projected, pressure will be exerted upon the shell so that it will slide along the core pipe 25. In such sliding action, it will simultaneously telescope tube 23 over the support 2. Eventually, the upper surface of the mass of composition cork will engage the inner face of the shell and the latter will begin to compress the same. This will continue until the mold cap, as shown in Fig. 7, is disposed within the face of the shell. With this positioning of the parts-which has been shown Y in Fig. 5-the pins or rods I9 may be disposed to lock the cap against movement, with respect to the shell.

-The latter, together with the enclosed core and sleeve, may now be placed in an oven and subjected to a temperature of approximately 300 F. AThe pressure under which the granules of composition cork are placed will vary from 300 to.600 pounds to the square inch. This will depend upon the depth to which the filler tubef At the same time, it will be observed that" 23 is filled with the mass, and the depth of the cap-shell assembly. In any event, after the assembly has been baked for minutes, it will be found that the adhesive with which the granules of composition are coated has served as a binder to maintain the entire sleeve as a unit, and .to secure the same against movement, with respect to the core which it encloses.

By withdrawing the rods or pins I9, the shell may be removed from the cap I4 and these parts may again be employed. The plug may be trimmed so as to remove any rough or uneven edges. Thereafterand as afore brought outthe tapered surfaces of the plug may be coated with graphite, and at this time, or else at the time the plug is associated with the case or other mounting member, its surfaces I3 may receive one or more coatings of lacquer or shellac.

In any event, there results from this treatment a resilient unit comprising the core and the sleeve ,which is concentrically disposed with respect to such core. This sleeve will be of even thickness throughout, and when employed inconnection with ordnance work, a plug results which embodies ample strength but which, at the same time, substantially completely disintegrates upon `being projected at ordinary velocity from the muzzle of a gun.

Now referring to the apparatus which conveniently manipulates the several parts, as heretofore described in connection with Figs. 4 and 5, attention is invited to Figs. 1, 2 and 3. In the nrst figures, it'will be seen that the tube or bed 20 has been shown as supported upon a deck 2?. Counterweights 23, by chains or other eX- ible supports, serve to mount the filling tube 23 yin a manner such that the weight of the same is counterbalanced. Thus, an operator will have no difficulty in raising this tube after the parts have assumeda position, such as has been shown in Fig. 5. Supports Slmay extend upwardly from the deck 2l, and in addition to suspending the counterweights 23, may mount gearing 3I or any other suitable mechanism whereby the pressure cylinder 2G may be projected and Iretraoted. A motor 32 may also connect with this gearing, and a control is, of course, provided for "governing the operations of the motor; l

. One of the supports 3i! may mount a receptacle 33 by means of a pivotally vsupported arm 34. '.With the arm shifted to onev position, the y'receptacle or bucket 33 may rotated around the end of this arm so that the spout portion', extending from the bucket, will traverse the spacebetween Athe pipe 25 and the filling tube.

In this manner, and without any difficulty, an

loperator will be enabled to evenly distribute the composition cork, or other material, throughout this space, so that after the latter is Elled, no further levelling of the mass is necessary. There- 4after, the arm 34 may be swung to one side. The pressure cylinder may now be projected and retracted, vas afore described, and in order to provide plugs including sleeves having even com- 'pres'sion and density factors with body characteristics of even compression and density.

Thus, among others, the several objects of the invention, as specifically afore noted, are achieved. Obviously, the structure ofA the 'plug and the material from which the same is` formed might be varied in numerous particulars, the .steps of the method might likewise be varied and the general construction of the machine. might be changed, as seems most expedient, without departing from the spirit of the invention, as defined by the claims.

And now, having described my invention, what I claim is:

1. A method of forming a plug having a unitary and frangible body comprising a central core and an encircling sleeve and which core and sleeve are formed of materials such as cork board and composition cork respectively, such method including the providing of the central core, mounting said core upon a base, encircling the core with a. mass of granules and which granules extend in the form of a column above the core, applying ra mould sleeve above the mass of granules and the base, projecting the mould sleeve toward the base to compress the ganules in the form of a sleeve having a height substantially equal to that of the core, locking the mould sleeve against movement with respect Vto the base to retain the mass of granules under compression, baking the entire plug enclosed within the mould sleeve and base and finally removing said base and mould sleeve from said plug assembly.

ing said core upon a base, encircling the core with a mass of granules to be received in and longitudinally and circumferentially compressed by a mould sleeve, such granule mass extending initially in the form of a column above the core,

A positioning the mould sleeve beyond the mass of granules, projecting such mould sleeve towards the base to compress the granules in the form of a sleeve having, a height substantially equal to that of the core and at the same time circum- `ierentially compress the mass around such core,

locking the mould sleeve against movement with respect to the base to maintain the granule mass under compressionand thereupon baking the entire plug body enclosed Within said mould sleeve.

FREDERICK CHARLES AUGUST OTT. 

